diff --git a/mockgen/mockgen.go b/mockgen/mockgen.go
index 79cb921c..8a4e6fd8 100644
--- a/mockgen/mockgen.go
+++ b/mockgen/mockgen.go
@@ -26,7 +26,6 @@ import (
 	"fmt"
 	"go/token"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -149,7 +148,7 @@ func main() {
 		g.mockNames = parseMockNames(*mockNames)
 	}
 	if *copyrightFile != "" {
-		header, err := ioutil.ReadFile(*copyrightFile)
+		header, err := os.ReadFile(*copyrightFile)
 		if err != nil {
 			log.Fatalf("Failed reading copyright file: %v", err)
 		}
@@ -165,7 +164,7 @@ func main() {
 		if err := os.MkdirAll(filepath.Dir(*destination), os.ModePerm); err != nil {
 			log.Fatalf("Unable to create directory: %v", err)
 		}
-		existing, err := ioutil.ReadFile(*destination)
+		existing, err := os.ReadFile(*destination)
 		if err != nil && !errors.Is(err, os.ErrNotExist) {
 			log.Fatalf("Failed reading pre-exiting destination file: %v", err)
 		}
@@ -704,7 +703,7 @@ func parsePackageImport(srcDir string) (string, error) {
 	if moduleMode != "off" {
 		currentDir := srcDir
 		for {
-			dat, err := ioutil.ReadFile(filepath.Join(currentDir, "go.mod"))
+			dat, err := os.ReadFile(filepath.Join(currentDir, "go.mod"))
 			if os.IsNotExist(err) {
 				if currentDir == filepath.Dir(currentDir) {
 					// at the root
diff --git a/mockgen/mockgen_test.go b/mockgen/mockgen_test.go
index 55566001..b75906ef 100644
--- a/mockgen/mockgen_test.go
+++ b/mockgen/mockgen_test.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -369,7 +368,7 @@ func Test_createPackageMap(t *testing.T) {
 }
 
 func TestParsePackageImport_FallbackGoPath(t *testing.T) {
-	goPath, err := ioutil.TempDir("", "gopath")
+	goPath, err := os.MkdirTemp("", "gopath")
 	if err != nil {
 		t.Error(err)
 	}
@@ -404,7 +403,7 @@ func TestParsePackageImport_FallbackMultiGoPath(t *testing.T) {
 	var goPathList []string
 
 	// first gopath
-	goPath, err := ioutil.TempDir("", "gopath1")
+	goPath, err := os.MkdirTemp("", "gopath1")
 	if err != nil {
 		t.Error(err)
 	}
@@ -421,7 +420,7 @@ func TestParsePackageImport_FallbackMultiGoPath(t *testing.T) {
 	}
 
 	// second gopath
-	goPath, err = ioutil.TempDir("", "gopath2")
+	goPath, err = os.MkdirTemp("", "gopath2")
 	if err != nil {
 		t.Error(err)
 	}
diff --git a/mockgen/parse.go b/mockgen/parse.go
index 21c0d70a..c13be566 100644
--- a/mockgen/parse.go
+++ b/mockgen/parse.go
@@ -26,8 +26,8 @@ import (
 	"go/parser"
 	"go/token"
 	"go/types"
-	"io/ioutil"
 	"log"
+	"os"
 	"path"
 	"path/filepath"
 	"strconv"
@@ -701,7 +701,7 @@ func isVariadic(f *ast.FuncType) bool {
 
 // packageNameOfDir get package import path via dir
 func packageNameOfDir(srcDir string) (string, error) {
-	files, err := ioutil.ReadDir(srcDir)
+	files, err := os.ReadDir(srcDir)
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/mockgen/reflect.go b/mockgen/reflect.go
index 4f86a151..1e310ec8 100644
--- a/mockgen/reflect.go
+++ b/mockgen/reflect.go
@@ -23,7 +23,6 @@ import (
 	"fmt"
 	"go/build"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -92,7 +91,7 @@ func writeProgram(importPath string, symbols []string) ([]byte, error) {
 
 // run the given program and parse the output as a model.Package.
 func run(program string) (*model.Package, error) {
-	f, err := ioutil.TempFile("", "")
+	f, err := os.CreateTemp("", "")
 	if err != nil {
 		return nil, err
 	}
@@ -133,7 +132,7 @@ func run(program string) (*model.Package, error) {
 // parses the output as a model.Package.
 func runInDir(program []byte, dir string) (*model.Package, error) {
 	// We use TempDir instead of TempFile so we can control the filename.
-	tmpDir, err := ioutil.TempDir(dir, "gomock_reflect_")
+	tmpDir, err := os.MkdirTemp(dir, "gomock_reflect_")
 	if err != nil {
 		return nil, err
 	}
@@ -149,7 +148,7 @@ func runInDir(program []byte, dir string) (*model.Package, error) {
 		progBinary += ".exe"
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(tmpDir, progSource), program, 0600); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, progSource), program, 0600); err != nil {
 		return nil, err
 	}